Beverage Cartridge

ABSTRACT

A cartridge containing one or more beverage ingredients and comprising an inlet for the introduction of an aqueous medium and an outlet for the beverage produced from the one or more beverage ingredients, the cartridge incorporating within a beverage flow path between the inlet and the outlet an eductor for entraining air into the beverage, the eductor comprising an aperture for producing a low pressure jet of the beverage.

CROSS-REFERENCE To RELATED APPLICATION

This application claims priority from United Kingdom Application GB0722039.5, filed Nov. 9, 2007, which is hereby incorporated herein byreference in its entirety.

FIELD

The present invention relates to improvements in cartridges forproducing beverages and, in particular, for producing beverages thatcomprise a fine bubble foam on the surface of the beverage, known ascrema.

BACKGROUND

EP1255685 describes a cartridge for use in a beverage preparationmachine for dispensing an espresso-style coffee beverage. The cartridgecomprises one or more restrictions for forming a jet or jets ofbeverage. At least one air inlet is provided and the jet (or jets) ofbeverage is passed over said at least one air inlet to thereby draw upair through the air inlet and entrain air bubbles in the flow ofbeverage. The flow of beverage then passes along an expansion chamber toan outlet where it is dispensed. In one embodiment, the cartridgefurther comprises within the beverage flowpath a surface upon which thebeverage impinges.

EP1440903 also describes a cartridge for use in a beverage preparationmachine for dispensing an espresso-style coffee beverage. The cartridgecomprises an eductor having an air inlet, and means for forming a lowpressure jet of beverage which is passed over said air inlet to therebydraw up air through the air inlet and entrain the air bubbles in theflow of beverage.

Whilst the cartridges described in EP1255685 and EP1440903 have beenfound to be effective, it would be desirable to produce an improvedcartridge wherein the quality of the crema delivered into the cup isimproved and/or controlled.

SUMMARY

Consequently, there is provided, in a first aspect, a cartridgecontaining one or more beverage ingredients and comprising an inlet forthe introduction of an aqueous medium and an outlet for the beverageproduced from the one or more beverage ingredients, the cartridgeincorporating within a beverage flow path between the inlet and theoutlet an eductor for entraining air into the beverage, the eductorcomprising an aperture for producing a low pressure jet of the beverage,at least one air inlet, a deflector channel downstream of the aperturefor imparting an asymmetrical flow to the beverage, and at least oneimpact surface onto which the jet of beverage impinges.

In a second aspect, there is provided a cartridge containing one or morebeverage ingredients and comprising an inlet for the introduction of anaqueous medium and an outlet for the beverage produced from the one ormore beverage ingredients, the cartridge incorporating within a beverageflow path between the inlet and the outlet an eductor for entraining airinto the beverage, the eductor comprising an aperture for producing areduced pressure jet of the beverage, at least one air inlet, and adeflecting channel downstream of the aperture, the cartridge furthercomprising a circulation chamber between the deflecting channel of theeductor and the outlet, the deflecting channel entering the circulationchamber from a periphery of said circulation chamber and the outlet ofthe cartridge being located at or near a centre of said circulationchamber, wherein the circulation chamber is shaped to cause the beverageexiting the deflecting channel of the eductor to whirl around thecirculation chamber before exiting the outlet.

In a further aspect, there is provided a cartridge containing one ormore beverage ingredients and comprising an inlet for the introductionof an aqueous medium and an outlet for the beverage produced from theone or more beverage ingredients, the cartridge incorporating within abeverage flow path between the inlet and the outlet an eductor forentraining air into the beverage, the eductor comprising an aperture forproducing a reduced pressure jet of the beverage, and at least one airinlet, the cartridge further comprising a circulation chamber betweenthe eductor and the outlet, the outlet being provided with a dischargespout comprising at least one fin for controlling an outflow directionof the beverage issuing from the cartridge.

In a further aspect, there is provided a cartridge containing one ormore beverage ingredients and comprising an inlet for the introductionof an aqueous medium and an outlet for the beverage produced from theone or more beverage ingredients, the cartridge incorporating within abeverage flow path between the inlet and the outlet an eductor forentraining air into the beverage, the eductor comprising an aperture forproducing a reduced pressure jet of the beverage, at least one air inletlying in a first plane, and a deflector channel downstream of the atleast one air inlet for imparting an asymmetrical flow to the beverage,the deflector channel comprising at least one impact surface lying in asecond plane, wherein the first and second planes are not parallel toone another.

In a further aspect, there is provided a method of varying the qualityand/or quantity of crema produced by a cartridge comprising the step ofvarying any one or more of the following parameters of the deflectorchannel:

-   -   the angle of or radius of curvature of a wall of the deflector        channel;    -   the angle between the path of the jet of beverage and the at        least one impact surface upon which it impinges;    -   the distance between the aperture and the point of impact of the        central region of the jet of beverage upon the at least one        impact surface;    -   the fluid velocity of the jet of beverage exiting the aperture;    -   the potential power dissipation of the jet of beverage on impact        with the impact surface;    -   the average air inclusion flow rate into the eductor; and/or    -   the pressure profile in the deflector channel.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the present invention will now be described, byway of example only, with reference to the accompanying drawings inwhich:

FIG. 1 is a cross-section view through a prior art beverage cartridge;

FIG. 2 is a perspective view from above of an outer member of thecartridge of FIG. 1;

FIG. 3 is a perspective view from above of the outer member of FIG. 2 inan inverted orientation;

FIG. 4 is a cross-sectional view of an inner member of the cartridge ofFIG. 1;

FIG. 5 is an enlarged cross-sectional view of a portion XVII of theinner member of FIG. 4;

FIG. 6 is a perspective view from above of the inner member of FIG. 4;

FIG. 7 is a perspective view from above of the inner member of FIG. 4 inan inverted orientation;

FIG. 8 is a perspective view of a portion of an interior of a prior artcartridge similar to FIG. 1;

FIG. 9 is a perspective view of a portion of an interior of anembodiment of a cartridge according to the present invention;

FIG. 10 a is a diagram of a computational fluid dynamic (CFD) analysisof beverage flow within the portion of cartridge shown in FIG. 8;

FIG. 10 b is an illustration of beverage flow within the portion ofcartridge shown in FIG. 8;

FIG. 11 a is a diagram of a computational fluid dynamic (CFD) analysisof beverage flow within the portion of cartridge shown in FIG. 9;

FIG. 11 b is an illustration of beverage flow within the portion ofcartridge shown in FIG. 9;

FIG. 12 a is a diagram of a CFD analysis of flow within an eductorchannel of the cartridge of FIG. 9;

FIG. 12 b is a diagram of a CFD analysis of flow within an eductorchannel of the cartridge of FIG. 1;

FIG. 13 a is a schematic top plan view of a portion of an interior ofthe cartridge of FIG. 1 (provided with four ribs according to anembodiment of the present invention);

FIG. 13 b is an illustration of the crema formed on a beverage producedusing the cartridge of FIG. 13 a;

FIG. 14 a is a schematic top plan view of a portion of an interior of acartridge according to a first embodiment of the present invention;

FIG. 14 b is an illustration of the crema formed on a beverage producedusing the cartridge of FIG. 14 a;

FIG. 15 a is a schematic top plan view of a portion of an interior of acartridge according to a second embodiment of the present invention;

FIG. 15 b is an illustration of the crema formed on a beverage producedusing the cartridge of FIG. 15 a;

FIG. 16 a is a schematic top plan view of a portion of an interior of acartridge according to a third embodiment of the present invention;

FIG. 16 b is an illustration of the crema formed on a beverage producedusing the cartridge of FIG. 16 a;

FIG. 17 a is a schematic top plan view of a portion of an interior of acartridge according to a fourth embodiment of the present invention;

FIG. 17 b is an illustration of the crema formed on a beverage producedusing the cartridge of FIG. 17 a;

FIG. 18 is a perspective view of a portion of an interior of a fifthembodiment of cartridge according to the present invention;

FIG. 19 is a perspective view of a portion of an interior of a sixthembodiment of cartridge according to the present invention;

FIG. 20 is an illustration of the crema result achieved using a modelcartridge as disclosed in Table 1b;

FIGS. 21 a-21 k are illustrations of the bubble size rating scalestandards used in evaluating foam;

FIGS. 22 a-22 e are illustrations of the foam coverage scale standardsused in evaluating foam;

FIGS. 23 a-23 d are illustrations of a target appearance for variousbeverage types;

FIG. 24 is a perspective view of an interior of a cartridge as discussedin Table 3;

FIGS. 25 a-25 g are perspective views of interiors of cartridges asdiscussed in Table 3; and

FIGS. 26 a-26 g are illustrations of a crema formed on beveragesproduced using the cartridges of FIGS. 25 a-25 g respectively.

DETAILED DESCRIPTION

FIGS. 1 to 8 illustrate a prior art cartridge 1 which is described indetail in the applicant's European patent publication EP1440903. Thecartridge 1 is particularly designed for use in dispensingespresso-style products such as roast and ground coffee where it isdesirable to produce a beverage having a froth of tiny bubbles known asa crema.

As shown in FIG. 1, the cartridge 1 generally comprises an outer member2 (shown in more detail in FIGS. 2 and 3), an inner member 3 (shown inmore detail in FIGS. 4 to 7) and a laminate 5. The outer member 2, innermember 3 and laminate 5 are assembled to form the cartridge 1 which hasan interior 120 for containing one or more beverage ingredients 200. Aninlet 27 and an outlet 43 are initially sealed by the laminate 5 and areopened in use by piercing or cutting portions of the laminate 5. Abeverage flow path between the inlet 27 and outlet 43 is defined byspatial inter-relationships between the outer member 2, inner member 3and laminate 5.

The overall shape of the cartridge 1 is generally circular ordisc-shaped.

As best shown in FIGS. 2 and 3, the outer member 2 generally comprises abowl-shaped shell 10 having a curved annular wall 13, a closed top 11and an open bottom 12. The annular wall 13 and closed top 11 togetherdefine a receptacle having an interior 34.

A hollow inwardly directed cylindrical extension 18 is provided in theclosed top 11 centred on the major axis X. An outwardly extendingshoulder 33 is formed in the outer member 2 towards the bottom 12. Theoutwardly extending shoulder 33 forms a secondary wall 15 co-axial withthe annular wall 13 so as to define an annular track forming a manifold16 between the secondary wall 15 and the annular wall 13. The manifold16 passes around the circumference of the outer member 2. A series ofslots 17 are provided in the annular wall 13 level with the manifold 16to provide gas and liquid communication between the manifold 16 and theinterior 34 of the outer member 2.

A lower end of the outwardly extending shoulder 33 is provided with anoutwardly extending flange 35.

As best shown in FIGS. 4 to 7, the inner member 3 comprises an annularframe 41 and a downwardly extending cylindrical funnel 40. The annularframe 41 comprises an outer rim 51 and an inner hub 52 joined by radialspokes 53. The inner hub 52 is integral with and extends from thecylindrical funnel 40. Filtration apertures 55 are formed in the annularframe 41 between the radial spokes 53. A filter 4 is disposed on theannular frame 41 so as to cover the filtration apertures 55. Passages 57are formed above the frame 41 between webs 54.

The cylindrical funnel 40 comprises an outer tube 42 surrounding aninner discharge spout 43. The outer tube 42 forms the exterior of thecylindrical funnel 40. The discharge spout 43 is joined to the outertube 42 at an upper end of the discharge spout 43 by means of an annularflange 47. The discharge spout 43 comprises an inlet 45 at an upper endwhich communicates with openings 56 of the passages 57 and an outlet 44at a lower end through which the prepared beverage is discharged into acup or other receptacle.

The inner member 3 spans between the outer member 2 and the laminate 5.

A rim 67 is provided upstanding from the annular flange 47 joining theouter tube 42 to the discharge spout 43. The rim 67 surrounds the inlet45 to the discharge spout 43 and defines an annular channel 69 betweenthe rim 67 and the upper portion of the outer tube 42. The rim 67 isprovided with an inwardly directed shoulder. At one point around thecircumference of the rim 67 an aperture 70 is provided in the form of aslot which extends from an upper edge of rim 67 to a point marginallybelow the level of the shoulder.

With particular reference to FIGS. 4 and 5, an air inlet 71 is providedin annular flange 47 circumferentially aligned with the aperture 70. Theair inlet 71 comprises an aperture passing through the flange 47 so asto provide communication between a point above the flange 47 and thevoid space below the flange 47 between the outer tube 42 and dischargespout 43. The air inlet 71 comprises an upper frusto-conical portion 73and a lower cylindrical portion 72.

On assembly, as shown in FIG. 1, the cylindrical extension 18 is seatedinside the support rim 67. A shoulder of the cylindrical extension 18bears against the upper edge of the support rim 67 of the inner member3. An interface 124 is thus formed between the inner member 3 and theouter member 2 comprising a face seal between the cylindrical extension18 and the support rim 67 which extends around nearly the wholecircumference of the cartridge 1. The seal between the cylindricalextension 18 and the support rim 67 is not fluid-tight though since theslot 70 in the support rim 67 extends through the support rim 67 anddownwardly to a point marginally below the shoulder. Consequently theinterface fit between the cylindrical extension 18 and the support rim67 transforms the slot 70 into a rectangular shaped aperture 128providing gas and liquid communication between the annular channel 69and the discharge spout 43.

To use the cartridge 1 it is first inserted into a beverage preparationmachine and the inlet 27 and outlet 43 are opened by piercing members ofthe beverage preparation machine which perforate and fold back thelaminate 5. An aqueous medium, typically water, under pressure entersthe cartridge 1 through the inlet 27. The water is directed to flowround the manifold 16 and into the interior 120 of the cartridge 1through the plurality of slots 17. The water mixes with the beverageingredients 200 contained therein. The water is at the same time forcedupwardly through the beverage ingredients. The beverage formed bypassage of the water through the beverage ingredients passes through thefilter 4 and filtration apertures 55 into the passages 57 lying abovethe annular frame 41.

The beverage then flows downwardly along the radial passages 57 andthrough the openings 56 and into the annular channel 69. From theannular channel 69 the beverage is forced under pressure through theaperture 128 by the back pressure of beverage collecting in the interior120 and passages 57. The beverage is thus forced through aperture 128 asa jet and into an expansion chamber formed by the upper end of thedischarge spout 43. The jet of beverage passes directly over the airinlet 71. As the beverage passes through the aperture the pressure ofthe beverage drops. As a result air is entrained into the beveragestream in the form of a multitude of small air bubbles as the air isdrawn up through the air inlet 71. The beverage issuing from theaperture 128 is funnelled downwards to the outlet 44 where the beverageis discharged into a receptacle such as a cup where the air bubbles formthe desired crema. Thus, the aperture 128 and the air inlet 71 togetherform an eductor which acts to entrain air into the beverage.

As shown in FIGS. 1, 5 and 8, the walls 70 a of the slot 70 arestraight-sided and are oriented such that the aperture 128 directs thejet of beverage into the upper portion of the discharge spout 43directly towards the centre of the discharge spout 43.

FIG. 9 illustrates a portion of a beverage cartridge according to anembodiment of the present invention. Many of the features of thecartridge are the same as the cartridge of FIG. 1 and will not bedescribed further in detail. For these features like numbering has beenused. The eductor and the discharge spout of the cartridge according tothe illustrated embodiments of the present invention have beenredesigned to improve and/or control crema quality.

As shown in FIG. 9, the discharge region of the cartridge comprises aneductor channel 80, circulation chamber 93 and the discharge spout 43.The walls 81 of the eductor channel 80 both in the region of the airinlet 71 and downstream of the air inlet 71 are curved such that thebeverage passing through the inlet aperture 128 of the eductor (formedfrom the slot 70 shown in the Figure as described above by theinteraction of the slot 70 with the outer member 2) and along thechannel 80 is forced through an angular deviation before enteringcirculation chamber 93. The circulation chamber 93 is formed by a regionof the inner member having a bounding wall 90 and a sloping floor 94.The sloping floor 94 slopes inwardly and downwardly towards thedischarge spout 43. The bounding wall 90 is generally spiral in shapehaving a portion 90 a of generally circular shape extending through anangle of approximately 270 degrees from an exit point 82 of the eductorchannel 80 and a portion 90 b of decreasing radius of curvature wherethe bounding wall 90 curves inwardly traversing the sloping floor 94 toterminate adjacent the central opening of the discharge spout 43. Theterminus of the bounding wall 90 b is coincident with the exit point 82of the eductor channel 80. Thus the bounding wall extends through 360degrees in total.

The eductor channel 80 is defined by two curved eductor walls 81 markedin the Figures as first wall 81 a and second wall 81 b. The walls 81 aand 81 b extend from the region of the slot 70, past air inlet 71 to theexit point 82 of the channel 80. In the embodiment shown the walls 81are curved in the opposite sense to the curve of the bounding wall 90 atthe exit point 82, although this is not essential and alternativeconfigurations may be adopted. The first wall 81 a is positioned on theinside of the curve of the eductor channel 80 and is thus of a shorterlength than the second wall 81 b. In the embodiment shown, the curvedwalls 81 are concentric with a common radial centre and thus exhibitdifferent radii of curvature, although this is not essential andalternative configurations may be adopted. In the illustratedembodiment, the radius of curvature of the centre line of the eductorchannel is substantially 2.00 mm. In addition, the channel 80 enters thecirculation chamber 93 in a tangential manner.

In the embodiment shown, due to its curvature and configuration, thesecond wall 81 b provides an impact surface substantially 1.23 mm alongthe centre line from the outlet of slot 70 through which the jet ofbeverage enters the eductor channel 80. The included angle of impactbetween the centre line along which a jet of beverage flows and theimpact surface is substantially 37.78 degrees.

A floor 74 of the eductor channel 80 is sloped downwardly towards theexit point 82 such that the height of the walls 81 of the eductorchannel 80 increase from the entrance to the exit point 82 of thechannel 80.

In the embodiment shown, the air inlet 71 is circular and has a diameterD. Alternatively, the air inlet may take any convenient shape, such as aD-shape or other convenient shape. The equivalent or effective diameterD of such a shape is calculated by taking the area A and determining Dfrom A=πr², where D=2r.

In use, beverage is dispensed from the cartridge using a beveragemachine as described above. However, the improved eductor and dischargespout region help improve and/or control the appearance and quantity ofthe crema generated. Beverage passing from the annular channel 69 isforced into a high velocity jet on passing through the aperture 128. Thejet of beverage then passes over the air inlet hole 71 causing airbubbles to be drawn up and entrained into the flow. The beverage flowwith air bubbles then directly impacts the second wall 81 b of theeductor channel 80 near the outlet of the air hole 71 at a high velocitycausing the flow to become highly turbulent and to fold over andcirculate within the eductor channel 80 interacting significantly withthe walls 81 b and 81 a before exiting at exit point 82. In addition,the impact of the jet on the walls of the eductor channel helps tocomplete entrainment of the air bubbles in the liquid and to break downlarger bubbles even before the jet exits the confines of the eductorchannel 80. Thus, the curved eductor channel 80 introduces an asymmetricnature to the flow dynamic. Also, since the eductor channel 80 isdownwardly directed by virtue of the sloping floor 74 and the aperture128 is located towards a top of the eductor channel 80, the asymmetricflow is encouraged to spiral within the eductor channel 80 as shown inthe CFD diagram of FIG. 12 a. This is in marked contrast to the computedflow pattern in the eductor channel of the cartridge of FIG. 1 shown inFIG. 12 b where the flow is largely directed straight along the eductorchannel without any significant vortexing, spiralling or asymmetry. Thishas a number of effects. The beverage in the curved eductor channel 80interacts far more with the walls 81 of the channel than when theeductor channel is straight. This helps to mix the liquid and air phasesof the beverage flow. Thus there is more opportunity for the bubble sizewithin the flow to be reduced and/or maintained at its initially smallersize. With a straight eductor channel it can be seen from FIG. 12 b thatthe flow in the centre of the eductor channel removed from the walls(where the air inlet 71 outputs) remains at a high velocity throughoutthe full length of the eductor channel. As a result the air bubblesemerging from the air inlet 71 tend to pass straight along the eductorchannel with minimal interaction with the liquid phase of the beverageor with the eductor channel walls. This has the disadvantage ofencouraging and/or providing an environment for bubble coalescence,increasing the size of bubbles in the flow of beverage. It has beenfound that the vortexing flow exiting the curved eductor channel 80leads to a more reproducible crema from cartridge to cartridge of higherand/or controlled quality.

After exiting the curved eductor channel 80 the flow of beveragecirculates within the circulation chamber 93 where it is encouraged bythe bounding wall 90 into a flow pattern as shown in FIGS. 11 a and 11b, wherein the flow rotates about the axis of the discharge spout 43whilst at the same time descending the circulation chamber and spouttowards the outlet such that the flow of beverage experiencescentrifugal forces. The flow of beverage then exits into the dischargespout 43 and into the waiting cup or receptacle.

The flow of the beverage around the circulation chamber 93 helps toorder the flow and maintain the structure of the flow prior to dischargethrough the spout 43. It has been found by experiment that in cartridgesaccording to some embodiments of the invention, the non-linear entry ofthe beverage into the circulation chamber 93 allows larger air bubblescontained within the beverage to migrate towards the centre of thechamber 93, preferentially by traversing across the upper region of thechamber 93 whilst beverage containing smaller bubbles is circulated atthe periphery of the chamber 93 nearer the bounding wall 90 anddownwards towards the discharge spout 43. The larger bubbles areconveyed to the centre of the chamber 93 where they coalesce and thencollapse. This is in marked contrast to the flow dynamic of the priorart cartridge of FIGS. 1 to 8 as shown in FIGS. 10 a and 10 b where theflow pattern within and directly above the discharge spout 43 has muchlarger bubble sizes wherein the larger bubbles tend to recirculate andare dispensed as part of the crema of the beverage.

It has also been found by experiment that the use of a curved eductortogether with a circulation chamber downstream of the eductor channelallows for the eductor to entrain air and control bubble size whilst thecirculation chamber helps to grade bubble size within the flow butwithout any significant additional entrainment of air. In tests, thecartridge of FIG. 9 was tested but with the eductor air inlet 71 blockedoff. The results showed that a fine crema was not produced simply bymeans of the presence of the circulation chamber. In other words bubbleentrainment was not occurring in the circulation chamber 93. This wasalso shown using CFD models.

A number of models of cartridge having eductor channels of differingdegrees of curvature were prepared. An experiment was then conducted tocompare the performance of a straight eductor channel against theseveral designs of curved eductor. The results are shown in Table 1a,with reference to FIGS. 13 a to 17 b.

TABLE 1a Distance Angle of from impact aperture 70 against Foam ratingFoam to impact eductor (0 = poor, volume Eductor Geometry point of jetwall Test no. 5 = Excellent) (ml) Comments Straight eductor,

 7.8 mm* N/A 1 3 15 See FIGS. 13a and Normal (centre) entry 2 2.5 20 13b. 3 2 18 Coarse foam, not very Average 2.5 17.7 stable. Curved eductorA

1.66 mm 29.3° 1 3 18 See FIGS. 14a and (radius 4.0 mm) 2 2 23 14b.Tangential entry 3 3 20 Coarse to medium Average 2.7 20.3 foam,relatively stable. Curved eductor B

1.23 mm 3.78° 1 3 18 See FIGS. 15a and (radius 2.5 mm) 2 3.5 23 15b.Tangential entry 3 3.5 16 Medium to fine stable Average 3.3 19.0 foam.Curved eductor B

 1.2 mm 36.9° 1 4 18 See FIGS. 16a and (radius 2.5 mm) 2 3.5 12 16b.Normal (centre) entry 3 4.5 15 Fine to very fine stable Average 4.0 15.0foam. Curved eductor C

0.87 mm 51.4° 1 3.5 15 See FIGS. 17a and (radius 1.5 mm) 2 4 14 17b.Tangential entry 3 4 16 Fine to very fine stable Average 3.8 15.0 foam.*Note: jet impact of straight eductor is against opposite side of outletchamber, not against eductor channel wall.

All models were constructed as full-size stereolithography (SLA)prototypes, therefore the results of crema obtained give a comparativereading but are not typical of the better performance achieved in thefinalised design implemented as a plastic injection moulding forproduction. The result of this finalised design is shown in Table 1b,along with an illustration (FIG. 20) of the crema result achieved.

TABLE 1b Distance Angle of from impact aperture 70 against Foam ratingFoam Production Eductor to impact eductor (0 = poor, volume Geometrypoint of jet wall Test no. 5 = Excellent) (ml) Comments Curved eductor B

1.23 mm 37.8° 1 4.25 5 See FIG. 20. (radius 2.5 mm) 2 4.75 5 Extremelyfine Tangential entry 3 4.75 5 and stable foam. Average 4.6 5.0

For each eductor geometry, the distance from the outlet of aperture 70along the centre line to impact point of jet (mm), angle of impactagainst eductor wall (degrees), test no., foam rating (0=poor,5=excellent), foam volume (ml) and comments are stated. The foam ratingis an incremental eleven point scale as typically applied to coffeebeverages, from 0 to 5 in 0.5 increments, assessed visually according tobubble size rating scale standards illustrated in FIGS. 21 a-21 k andthe foam coverage scale standards illustrated in FIGS. 22 a-22 e.

The experimental results show that the quality of crema increases withan increase in the degree of curvature of the eductor channel. This isalso accompanied by a slight reduction in the quantity of cremaproduced.

The applicant has found that by optimising one or more of a number ofparameters of, or within, the eductor channel, an improvement (orcontrolled reduction) in the quality of crema can be obtained. Forexample, the results illustrate the beneficial effects achieved whenadjusting the radius of curvature of the eductor (and walls of theeductor), impact surface angle, and distance of jet from aperture toimpact surface. In addition, the applicant has found beneficial effectsfrom controlling operating parameters within the eductor channel such asthe position and distance of the air inlet along the eductor channel,fluid velocity (from 1.25 to 100 m/s), amount of air entrained (333 to13,333 mm³/s), and potential power dissipation (0.002 to 15W). A jet (ata velocity of 17.13 m/s) impacting on the outside wall of the curvedeductor channel in close proximity to the air inlet has provedparticularly beneficial to the quality of crema obtained.

In contrast, the jet of beverage in the straight eductor passes over theair inlet, along the eductor channel and into the outlet chamber withoutimpacting on the eductor channel walls. This causes a greater amount ofair entrainment in the eductor channel, but with poorer mixing action ofthe air/water phases of the beverage in the outlet chamber.

Conversely, with a curved eductor, as the degree of curvature increases(with all other features held the same) then the angle of jet impactagainst the wall increases and the impact point moves closer to the jetaperture and air inlet hole. As the jet impacts on the wall, itundergoes a change in shape and direction which promotes betterturbulent shearing and mixing action of the air/water phases in theeductor channel. Also, as the impact point becomes closer to the airinlet then the amount of air entrained is reduced due to reflected backpressure. The applicant believes that the reduced quantity of airentrained, combined with more efficient mixing and turbulent shearing,results in the observed finer crema. Conversely, with less efficientmixing, lower turbulent shearing or less separation of larger bubbles, acrema with larger bubbles may be formed.

It will be appreciated by those skilled in the art that manyalternatives to the preferred embodiments described are possible. Forexample, although the eductor designs presented above are curved, theycould take any form that causes the beverage to be forced through anangular deviation within the eductor (e.g. a dog leg or labyrinthineform). In addition, the pressure differentials set up in the eductor candetermine the appropriate positioning of the air inlet so as to controlthe amount of air inducted and entrained in the beverage. It will beappreciated also that any one or more of the length, height,cross-sectional and/or longitudinal shape and/or area, or volume of theeductor may be varied, as may the positioning of the air inlet, thecross sectional area and/or shape of the air inlet, the area and/orangle and/or distance from the aperture of the impact surface.Furthermore, the velocity of the jet of beverage and the pressureprofiles in the eductor may be varied. These variations enable theeductor of a beverage cartridge to be optimised according to the type,quality and quantity of crema desired for a given beverage type.

As a result, cartridges can have eductor designs tailored dependent uponthe type of crema desired to be produced with a particular beverage. Anexample of how to characterise crema by beverage type is described inTable 2 and illustrated in FIGS. 23 a-23 d.

TABLE 2 FOAM BUBBLE SIZE QUANTITY TARGET DRINK FOAM DESCRIPTION (mm)(ml) APPEARANCE Espresso Uniform, tiny, virtually- 80% < 0.5  5-20 SeeFIG. 23a indistinguishable bubbles 20% 0.5-1.5 (9-25% with 1-2 smallbubbles. total coffee) Full surface coverage of stable foam. Colour &marbling not specified Café Crema Mixed small, medium & 25% < 1.0 15-25See FIG. 23b 1-2 open large bubbles. 60% 1-1.5 (10-20% Full surfacecoverage of 15% 1.5-5.0 total coffee) stable foam. Cappuccino Mixedsmall, medium & 25% < 1.0 40-70 See FIG. 23c 1-2 open large bubbles. 60%1-1.5 (40-55% Full surface coverage of 15% 1.5-5.0 total milk) stablefoam. Slightly resistant to deformation in stirring with a spoon. LatteUniform, tiny, bubbles 80% < 0.5 20-40 See FIG. 23d with 1-2 smallbubbles. 20% 0.5-1.5 (15-25% Full surface coverage of total milk) stablefoam.

Once the desired crema has been formed in the beverage using a suitablyoptimised eductor channel, it is important to control the onward path ofthe beverage through the cartridge to the outlet so as to eliminate orreduce as far as possible any deterioration of the crema.

As mentioned above, upon exit from the eductor channel, the circulatoryflow of the beverage around the circulation chamber helps to increasethe robustness of the flow structure of the beverage prior to dischargethrough the spout, maintaining as far as possible the quality andquantity of crema.

In order to control the beverage on issue from the outlet spout of thecartridge, control fins are beneficially employed. FIGS. 18 and 19illustrate further embodiments of cartridges incorporating control fins.

In FIG. 18, as with the first embodiment of cartridge of FIG. 9, thecartridge is provided with an eductor having a curved eductor channel 80that opens tangentially into the chamber defining the circulationchamber 93. However, in this embodiment the discharge spout 43 isprovided with four ribs or fins 100. The fins 100 are orientatedlongitudinally along the spout 43 and are equi-spaced around the spout'scircumference. Each fin 100 extends part way towards the centre of thespout 43 such that a central opening 101 or free region is maintainedwithin the spout 43. Each fin 100 is shown tapered so as to have atriangular shape in elevation with the distance of the fin from the wallof the spout 43 increasing as one travels down the spout 43. It isimportant that each fin 100 is of tapered shape so as to arrest thecirculation gradually. It has been found in use that the presence of thefins 100 greatly improves the delivery of the beverage into the waitingreceptacle. In particular, the cartridge with the fins 100 issues astream of beverage which is more tightly controlled and results in lesssplashing. An advantage over prior art designs is that the fins 100avoid the production of an expanding conical spray of beverage from thecartridge which can lead to beverage missing the intended receptacle andcan also lead to disruption of any crema present on the beverage in thereceptacle.

FIG. 19 illustrates a further embodiment of cartridge which is similarto that shown in FIG. 18. In this embodiment six fins 100 are providedon the discharge spout wall equi-spaced around the circumference. Thefins 100 are trapezoidal in shape in elevation.

A number of models (examples of which are shown in FIGS. 24 and 25 a-25g) were tested with differing rib configurations. The results arediscussed in Table 3 and the resultant foam is illustrated in FIGS. 26a-26 g.

TABLE 3 Outlet Design Number & Open (Reference no.) type of ribs areaFlow Characteristics Foam FIG. 24 NO RIBS 8.88 mm2 Directionconsistency: VERY Photograph not taken - (Ref: 51) POOR. No discernablemain Insufficient drink/foam in cup. stream. Coffee leaves disc outletin a spinning cone with an inclusive angle of 80 degrees Stability: VERYPOOR Cup delivery: VERY POOR - most of drink misses the cup. FIG. 25a 1CROSS RIB 7.50 mm2 Direction consistency: POOR. FIG. 26a (Ref. 55) Mainstream direction tends to vary by up to +/−25 to 30 degrees to thevertical. Stability: POOR - Evidence can be seen of two streams inopposite directions “competing” against each other. One stream isdominant. Cup delivery: VERY POOR Significant side spray outside of cup.FIG. 25b 3 CROSS 6.84 mm2 Direction consistency: GOOD. FIG. 26b (Ref:56) RIBS Main stream less than 10 degrees from vertical Stability:FAIR - some movement of mainstream within 10 degree limit, influenced bythe pull from a strong side spray. Cup delivery: POOR - Some side sprayoutside of cup. FIG. 25c 4 SHALLOW 6.56 mm2 Direction consistency: GOOD.FIG. 26c (Ref: 49) CROSS RIBS Main stream 10 degrees from verticalStability: FAIR - Slight main stream movement. Lots of fine side sprayCup delivery: VERY POOR - Significant side spray outside of cup. FIG.25d 4 DEEP 6.20 mm2 Direction consistency: GOOD. FIG. 26d (Ref: 58)CROSS RIBS Maximum 10 degrees from vertical Stability: FAIR - streamrapidly oscillates in several directions but within +/−10 degrees limit.(Possibly due to separate vortex flows established in each quadrant) Cupdelivery: FAIR to GOOD - Little side spray, mostly inside the cup. FIG.25e 6 CROSS 4.92 mm2 Direction consistency: GOOD. FIG. 26e (Ref: 65)RIBS About 5-10 degrees from vertical Stability: GOOD - main stream verystable, but with fine side spray. Cup delivery: VERY POOR - significantside spray outside cup. FIG. 25f 4 OPEN RIBS 7.29 mm2 Directionconsistency: GOOD. FIG. 26f (Ref: 50) About 10 degrees from verticalStability: FAIR to GOOD - main stream moves by maximum 5 degrees. Cupdelivery: GOOD- all in cup, no side spray. FIG. 25g 6 OPEN RIBS 6.14 mm2Direction consistency: VERY FIG. 26g (Ref: 63) GOOD. Less than 5 degreesfrom vertical Stability: VERY GOOD - stream hardly moves. Cup delivery:VERY GOOD - all in cup no side spray.

For each outlet design (listed by reference no.), the number and type ofribs, open area, flow characteristics and an illustration of theresultant foam are given.

The experimental results (and further experimentation) show that betweenfour and eight fins are beneficial in producing a more directable andconfined flow of beverage issuing from the cartridge without anynoticeable deterioration in crema quality or quantity.

Although several embodiments of cartridge have been described above, anyone or more or all of the features described (and/or claimed in theappended claims) may be provided in isolation or in various combinationsin any of the embodiments. As such, any one or more of these featuresmay be removed, substituted and/or added to any of the featurecombinations described and/or claimed. For the avoidance of doubt, anyof the features of any embodiment may be combined with any other featurefrom any of the embodiments.

Whilst preferred embodiments of the present invention have beendescribed above and illustrated in the drawings, these are by way ofexample only and non-limiting. It will be appreciated by those skilledin the art that many alternatives are possible within the scope of theinvention, as set out in the appended claims.

1. A cartridge containing one or more beverage ingredients andcomprising an inlet for the introduction of an aqueous medium and anoutlet for the beverage produced from the one or more beverageingredients, the cartridge incorporating within a beverage flow pathbetween the inlet and the outlet an eductor for entraining air into thebeverage, the eductor comprising an aperture for producing a jet of thebeverage, means for producing a pressure reduction of the jet ofbeverage, at least one air inlet, a deflector channel downstream of theaperture for imparting an asymmetrical flow to the beverage, and atleast one impact surface onto which the jet of beverage impinges.
 2. Acartridge as claimed in claim 1 wherein the cartridge further comprisesa circulation chamber between the eductor and the outlet.
 3. A cartridgeas claimed in claim 2 wherein the deflector channel of the eductorenters the circulation chamber tangentially.
 4. A cartridge as claimedin claim 1 wherein the deflector channel of the eductor comprises atleast one wall which is curved or has a curved portion or curvedportions.
 5. A cartridge as claimed in claim 4 wherein the deflectorchannel of the eductor comprises side walls which are curved or eachhave a curved portion or curved portions.
 6. A cartridge as claimed inclaim 4 wherein the curved wall or at least one of the curved portionsof wall has a radius of curvature of from 1.50 to 5.50 mm.
 7. Acartridge as claimed in claim 6 wherein the radius of curvature is from2.00 to 3.00 mm.
 8. A cartridge as claimed in claim 7 wherein the radiusof curvature is substantially 2.50 mm.
 9. A cartridge as claimed inclaim 1 wherein the deflector channel of the eductor enters thecirculation chamber normally.
 10. A cartridge as claimed in claim 1wherein the deflector channel of the eductor comprises at least one wallhaving a planar portion or planar portions.
 11. A cartridge as claimedin claim 1 wherein the deflector channel of the eductor comprises sidewalls which have a planar portion or planar portions.
 12. A cartridge asclaimed in claim 1 wherein at least part of a wall of the deflectorchannel is the at least one impact surface.
 13. A cartridge as claimedin claim 1 wherein the angle between the path of the jet of beverage andthe at least one impact surface upon which it impinges is an includedangle of from 1 to 90 degrees.
 14. A cartridge as claimed in claim 13wherein the included angle is from 20 to 60 degrees.
 15. A cartridge asclaimed in claim 14 wherein the included angle is substantially from 36to 39 degrees.
 16. A cartridge as claimed in claim 15 wherein theincluded angle is substantially 37.78 degrees.
 17. A cartridge asclaimed in claim 1 wherein the distance between an outlet of theaperture and a point of impact of a central region of the jet ofbeverage upon the at least one impact surface is from 0.60 to 7.80 mm.18. A cartridge as claimed in claim 17 wherein the distance is from 0.87to 2.08 mm.
 19. A cartridge as claimed in claim 18 wherein the distanceis substantially 1.23 mm.
 20. A cartridge as claimed in claim 1 whereinthe equivalent or effective diameter of the air inlet is D and thedistance between the aperture and a point of impact of a central regionof the jet of beverage upon the at least one impact surface is from 0.1D to 2.5 D.
 21. A cartridge as claimed in claim 20 wherein the distanceis from 0.2 D to 1.5 D.
 22. A cartridge as claimed in claim 21 whereinthe distance is substantially 0.44 D.
 23. A cartridge as claimed inclaim 1 wherein in use a fluid velocity of the jet of beverage exitingthe aperture is from 1.25 m/s to 100.00 m/s.
 24. A cartridge as claimedin claim 23 wherein in use the fluid velocity is from 6.90 m/s to 35.00m/s.
 25. A cartridge as claimed in claim 24 wherein in use the fluidvelocity is substantially 17.13 m/s.
 26. A cartridge as claimed in claim1 wherein in use a potential power dissipation of the jet of beverage onimpact with the impact surface is from 0.002 W to 15.0 W.
 27. Acartridge as claimed in claim 26 wherein in use the potential powerdissipation is from 0.1 W to 5.0 W.
 28. A cartridge as claimed in claim27 wherein in use the potential power dissipation is substantially 0.34W.
 29. A cartridge as claimed in claim 1 wherein in use an average airinclusion flow rate into the eductor is from 333 mm³/s to 13,333 mm³/s.30. A cartridge as claimed in claim 29 wherein in use the average airinclusion flow rate is from 667mm³/s to 6,667mm³/s.
 31. A cartridge asclaimed in or claim 30 wherein in use the average air inclusion flowrate is substantially 1,233mm³/s.
 32. A cartridge containing one or morebeverage ingredients and comprising an inlet for the introduction of anaqueous medium and an outlet for the beverage produced from the one ormore beverage ingredients, the cartridge incorporating within a beverageflow path between the inlet and the outlet an eductor for entraining airinto the beverage, the eductor comprising an aperture for producing ajet of the beverage, means for producing a pressure reduction of the jetof beverage, at least one air inlet, and a deflecting channel downstreamof the aperture, the cartridge further comprising a circulation chamberbetween the deflecting channel of the eductor and the outlet, thedeflecting channel entering the circulation chamber from a periphery ofsaid circulation chamber and the outlet of the cartridge being locatedat or near a centre of said circulation chamber, wherein the circulationchamber is shaped to cause the beverage exiting the deflecting channelof the eductor to whirl around the circulation chamber before exitingthe outlet.
 33. A cartridge containing one or more beverage ingredientsand comprising an inlet for the introduction of an aqueous medium and anoutlet for the beverage produced from the one or more beverageingredients, the cartridge incorporating within a beverage flow pathbetween the inlet and the outlet an eductor for entraining air into thebeverage, the eductor comprising an aperture for producing a jet of thebeverage, means for producing a pressure reduction of the jet ofbeverage, and at least one air inlet, the cartridge further comprising acirculation chamber between the eductor and the outlet, the outlet beingprovided with a discharge spout comprising at least one fin forcontrolling an outflow direction of the beverage issuing from thecartridge.
 34. A cartridge as claimed in claim 33 wherein the at leastone fin is tapered.
 35. (canceled)
 36. A cartridge as claimed in claim34 wherein the taper of the at least one fin is such that the distanceof a tip or edge of the fin from a root of the fin increases along thelength of the of the fin in the direction of the beverage flow pathbetween inlet and outlet.
 37. A cartridge as claimed in claim 34 whereinthe taper of the at least one fin is such that it controllably arrests acirculatory motion imparted to the beverage in the circulation chamberprior to the beverage issuing from the cartridge.
 38. A cartridge asclaimed in claim 33 wherein the at least one fin stops short oftraversing the outlet so as to maintain a central opening.
 39. Acartridge as claimed in claim 33 wherein the discharge spout has fourfins.
 40. A cartridge as claimed in claim 33 wherein the discharge spouthas six fins.
 41. A cartridge containing one or more beverageingredients and comprising an inlet for the introduction of an aqueousmedium and an outlet for the beverage produced from the one or morebeverage ingredients, the cartridge incorporating within a beverage flowpath between the inlet and the outlet an eductor for entraining air intothe beverage, the eductor comprising an aperture for producing a jet ofthe beverage, means for producing a pressure reduction of the jet ofbeverage, at least one air inlet lying in a first plane, and a deflectorchannel downstream of the at least one air inlet for imparting anasymmetrical flow to the beverage, the deflector channel comprising atleast one impact surface lying in a second plane, wherein the first andsecond planes are not parallel to one another.
 42. A cartridge asclaimed in claim 41 wherein the cartridge further comprises acirculation chamber between the eductor and the outlet.
 43. A method ofvarying the quality and/or quantity of crema produced by a cartridge,the cartridge containing one or more beverage ingredients and comprisingan inlet for the introduction of an aqueous medium and an outlet for thebeverage produced from the one or more beverage ingredients, thecartridge incorporating within a beverage flow path between the inletand the outlet an eductor for entraining air into the beverage, theeductor comprising an aperture for producing a jet of the beverage,means for producing a pressure reduction of the jet of beverage, atleast one air inlet, a deflector channel downstream of the aperture forimparting an asymmetrical flow to the beverage, and at least one impactsurface onto which the jet of beverage impinges; the method comprisingthe step of varying one or more of: an angle of a wall of the deflectorchannel; a radius of curvature of a wall of the deflector channel; anangle between the path of the jet of beverage and the at least oneimpact surface upon which it impinges; an distance between the apertureand the point of impact of the central region of the jet of beverageupon the at least one impact surface; the fluid velocity of the jet ofbeverage exiting the aperture; the potential power dissipation of thejet of beverage on impact with the impact surface; the average airinclusion flow rate into the eductor; and/or the pressure profile in thedeflector channel.
 44. The cartridge as claimed in claim 1 wherein abeverage produced from the cartridge comprises crema or foam.
 45. Thecartridge as claimed in claim 1 wherein a beverage produced from thecartridge comprises coffee, chocolate or milk beverage comprising cremaor foam.
 46. The cartridge as claimed in wherein the cartridge isconfigured to be inserted into a beverage preparation machine.
 47. Amethod of producing a beverage using the cartridge of claim 1 comprisingthe steps of introducing an aqueous medium into the cartridge throughthe inlet and; dispensing the beverage from the outlet, wherein thebeverage comprises a crema or foam.
 48. (canceled)
 49. (canceled) 50.(canceled)